1. Field of the Invention
The present invention relates to a thermal head.
2. Related Background Art
A thermal head is used for thermosensitive recording of photographic printers such as rewrite printers, card printers, video printers, bar code printers, label printers, facsimiles, ticket-vending machines.
This type of thermal head performs printing on a medium and eliminates printed information by heating a printing part to a predetermined temperature. Specifically, a thermal head selectively applies voltage to a single or multiple heat elements, which are linearly arranged, to cause them to generate heat and, with the resulting heat energy, prints characters and pictures on a heat-responsive medium, or erases printed items thereon.
Japanese Patent Application Laid-Open No. 10-71737 discloses a thermal head in which an electric conductor and a heat element are formed in this order on a ceramics substrate such as alumina. Moreover, Japanese Patent Application Laid-Open No. 7-125277 discloses a thermal head in which an electrically conductive material is formed on a heat element.
Further, Japanese Patent Application Laid-Open No. 10-71737 and Japanese Patent Application Laid-Open No. 7-125277 disclose a silver electrode containing a glass component as an electric conductor provided in a thermal head. As a method of forming the common electrode and lead electrode of such thermal head, a screen printing method, an electrolytic plating method, and a method of patterning by photolithography are used.